Method and apparatus utilizing highfrequency electrical energy in shoemaking



Aprfifi 1953 R. M. osBoRN 2,633,536

' METHOD AND APPARATUS UTILIZING HIGH-FREQUENCY ELECTRICAL ENERGY IN SHOEMAKING .6 Sheets-Sheet 1 Filed. D900 24, 1947 R. M. OSBORN METHOD AND APPARA Filed Dec. 24, 1947 Aprfi "P7, 1953 TUS UTILIZING HIGH-FREQUENCY ELECTRICAL ENERGY IN SHOEMAKING 5 Sheets-Sheet 2 Filed Dec. 24. 1947 M 9 953 R. M. osaem: fi fi METHOD AND APPARATUS UTILIZING HIGH-FREQUENCY ELECTRICAL ENERGY IN SHOEMAKING 3 Sheets-Sheet 5 HIGH FREQUENCY OSCILLATOR Patented Apr. 7, 1953 METHOD AND APPARATUS UTILIZING HIGH- FREQUENCY ELECTRICAL ENERGY IN SHOEMAKING Robert M. Osborn, Inglewood, Calif., assignor to United Shoe Machinery Corporation, Flemington, N. J., a corporation of New Jersey Application December 24, 1947, Serial No. 793,656

(01. lit-12.4)

20 Claims.

This invention relates to an improvement in the art of and apparatus for making shoes, and more particularly to the lasting of shoes and the provision therein of stiffened upper portions. The invention is herein illustrated by reference to the lasting and upper-stiffening of toe portions of Goodyear welt type shoes, but it is equally applicable to other parts of such shoes, and to other types of shoes as well.

In accordance with the method herein illustrated of practicing the invention, the shoe upper is treated for stiffening purposes while an adhesive bond is formed for securing th shoe parts in lasted relation by means of heat applied simultaneously in both localities. Thus, prior to the lasting operation an initially limp thermoactive stiffener member is incorporated in the upper of a shoe and later, with the shoe upper worked into conformity with the last and held there, this material is heat activated preferably, and as herein illustrated, by means of a high-frequency electric field. Preferably, 'the field is applied as a step tied in with the lasting operation, while the shoe is under the influence of the lasting means, and simultaneously with the activation of the stiffener, the shoe parts are bonded together adhesively by the effect of the field in activating a layer of thermoactive adhesive previously applied between the shoe parts, thus combining into a single operation the setting up of the stiffener and the securing of the shoe upper in a lasted condition, Without a separate handling of the shoe. Following the lasting operation, the shoe will then be in condition for inseaming or other succeeding operations. The term activate as applied herein with relation to producing an effect on an adhesive or stiffener material has reference to the step, utilizing, for example, an agent such as a solvent, a field or the heat produced by a field, of placing the adhesive in condition for producing a bond or the stiffener in condition for hardening or becoming stiff as a result of the step of activation.

It has been the common practice in making shoes to incorporate into the upper thereof a limp stiffener blank of a suitable heat or solvent activatable material and of activating this material as a step immediately preceding the pulling-over or related operation during which the shoe upper stock is tensioned over a last. In most instances the stiffener material must be reactivated a second time immediately prior to the lasting operation when the upper stock is finally conformed to the last and attached marginally to the insole. This practice requiring separate activation treatment of the stiflener material is not particularly efficient and requires extra time and the tying up unnecessarily of plant facilities. Furthermore, there is a related problem, arising especially in the case of toe lasting with the Goodyear welt type shoe. which centers around the process of securing the marginal toe portion of the she upper to the insole during toe lasting. After the upper stock has been wiped upwardly of the last and inwardly over the insole feather and held there under the pressure of the wiping means, it is the common practice, for example, tentatively to attach the overlasted margin of the upper stock to the insole by means of a length of wire stretched tightly around the forepart of a shoe against the base of the upturned portion of the upper stock bearing against the insole rib, the wire being anchored at its ends by tacks driven into the last bottom through the insole. In the inseaming operation which follows, the upper stock is permanently attached to the insole with a welt extension strip by sewing through the welt strip, the upper and the insole rib. It may be seen therefore that application of the Wire or other temporary securing means involves an additional step in the overall process and since it usually may not be removed until after the inseaming operation it is often bothersome for this reason. Thus, it has been contemplated that the elimination, as detached operations, of the separate activation of the upper stiffener material and of the application of the wire or other lasting-attaching means affords the basis of considerable time-saving in the manufacture of shoes, a. concern of the invention.

Accordingly, it is an object of this invention to provide an improved method of making shoes in which the process of activation of the stiffener material, in its relation to lasting, may be greatly facilitated and more closely knit into the shoe manufacturing process as a whole.

A further object is for the provision of such a method adapted for the combination into a single machine process, in conjunction with a lasting operation, of activating the shoe upperstiffener material simultaneously with the formation of a bond, in lasting, between th upper and the insole, thereby to accelerate the preparation of the shoe for a subsequent operation such as inseaming.

In one of its aspects the invention provides a method wherein thermoactive stiffener material incorporated while lim in the upper between doubler and lining when assembling the upper stock prior to the lasting operation may be stiffened by means of heat, preferably, and as herein illustrated, that produced by a high-frequency field, while the shoe is still under the influence of the working or lasting means. In accordance with one aspect of the method, simultaneously with the activation of the stiffener material a bond will be produced, for lasting purposes, between the overlasted margin of the shoe upper and the insole margin, for example, by the effect of the field in activating an adhesive previously applied between the parts, and it may be, in accordance with selected practice, that the parts of the shoe upper will likewise be bonded together at the same time. Because of the resulting efficiency of the method it is contemplated that a cheaper high-quality product may be proneed.

A further object of the invention is to provide apparatus adapted principally for implementing the practice of the foregoing method and by means of which stiffener material incorporated into the upper of the shoe prior to the lasting operation and an adhesive previously applied between the upper and insole margin may be simultaneously activated in a high-frequency field while the shoe is under the influence of the lasting means, without requiring separate handling.

Still another object of the invention is for the provision of safe and efficient apparatus of this character wherein high-frequency energy will not be picked up by the purely mechanical parts of the machine, thereby avoiding undue loss of highfrequency electrical energy and danger of burning the operator, and wherein the desired degree of uniformity of the field in the work may be realized.

In accordance with these objects, a feature of the invention resides in a lasting machine for carrying out the foregoing method, in which a grounded electrode is embodied in the wipers, a second grounded electrode in a shoe support or correspondingly located member (a toe support in the case of toe lasting as herein illustrated) and a third intervening high-voltage electrode is adapted for positioning preferably adjacent to the outer surface of the shoe, around the shoe forepart in the case of the illustrated practice of toe lasting. Effectively grounding the two outer electrodes as stated has the advantage that the surrounding metal parts of the machine are effectively isolated from the components carrying high-frequency currents, thereby preventing electrical pickup on such parts. Other advantages include the adaptability of the invention for incorporation into existing types of lasting machines available commercially, the fact that there need be no material change in the basic manner of operating such machines when so modified, and others.

The invention has been illustrated as embodied in a bed-lasting machine of a well-known type, the features of which are disclosed in various United States Letters Patent including Letters Patent No. 1,284,870, granted November 12, 1918, upon an application of Matthias Brock. In accordance with the construction shown, by which the apparatus is adapted for toe lasting as aforesaid, the usual toe rest in such a machine has been replaced by a similarly constructed member carrying an electrode preferably placed at or near radio-frequency ground potential. The wipers comprise the other grounded electrode, and a loop conductor having a forward portion which is U-shaped is positioned at an intermediate location and extends approximately the length of the stiffener material, around the outside of the forepart of a shoe inserted in the machine.

In practicing the method of the invention with such a machine the wipers will be employed in their usual capacity to wipe the upper stock of the toe end of the shoe upwardly and then in-- wardly over the marginal edge or feather of the insole whereupon the parts will be pressed together compactly by the wipers and retained in this position for the ensuing period of application of high-frequency energy to the electrodes. During this period the stiffener material will become heated by virtue of the well-known dielectric heating effect of a field which, in this case, will extend respectively between the intervening electrode member and the wipers (acting as an electrode), and toe-rest electrode members. The field, it has been found, will be of such a configuration as simultaneously to heat-activatea layer of cement which has been previously applied between the insole margin and the marginof the overlasted upper stock and similarly where cement has been applied between the outer surface of the insole rib and the upstanding portion of the overlasted upper for the purpose of increasing the bonding area. When the cement has become set, as it will very promptly, and a bond formed between the parts the shoe may be removed from the machine ready for further operations, free of wire or tacks and the like. De

pending upon the high-frequency power delivered to the electrodes the entire operation may consume only seconds, the time requirement being determined to a certain extent also by the setting time of the particular adhesive used, in order that the parts may hold together upon removal from the machine.

These and other features, objects and advantages of the invention, including various novel subcombinations and details of construction, will be further apparent from the following description which is based upon the accompanying drawings, in which Fig. 1 is a perspective view of a shoe of the Goodyear welt type after it has been subjected to the pulling-over and side-lasting operations and is ready for the steps of toe-lasting and the activation of a box-toe stiffener in accordance with this invention;

Fig. 2 is a perspective View of the operating instrumentalities of a toe-lasting machine embodying the invention, showing a shoe in operative position;

Fig. 3 is a plan view of the bottom of the forepart of a shoe as it is presented to the electrodes for purposes of the invention;

Fig. 4 is a vertical section taken on the line IV-IV of Fig. 3; and

Fig. 5 is a side elevation view of a well-known type of bed-lasting machine modified in accordance with the invention.

As herein described, the method of the invention involves the steps of assembling the shoe upper on a last carrying an insole, with a limp thermoactive stiffener blank incorporated in the toe portion of the upper and with a'l'ayerof thermoactive adhesive applied to the insole margin and preferably to the outer surface of the insole rib as well, to the inner surface of the overlasted margin of the upper, i. e., to the exposed face of the lining, and sometimes marginally between the upper leather and the doubler. In some cases it may be-preferable to avoid the use of cement in the latter position and this may be done conveniently by sewing together initially the upper stock by a marginal seam which will secure the upper leather to the other pieces. If desired, a coating of cement may also be applied marginally between the stiffener piece and the lining and doubler respectively, although in the use of a preferred class of stiffener materials there will usually be sufficient adhesive action of the stiffener material to hold the lining and doubler in bonded relation thereto after the stiffener has been activated in a high-frequency field as in accordance with the method.

Materials of the type especially suited for stiffening purposes are disclosed in United States Letters Patent No. 2,406,738, granted September 3, 1946, upon the application of John J. Brophy. For the adhesive various types may be used. Preferably the adhesive selected should become heated readily in a high-frequency field and set up rapidly thereafter.

The adhesive may be most conveniently applied in solution by brushing or spraying it onto the shoe parts and allowed to dry, at any time prior to assembling the upper on the last and preferably, but not necessarily, before the stiffener blank has been incorporated therewith. A shoe of the Goodyear welt type prepared in this manner and assembled on the last has been illustrated in Fig. 1. As shown, the shoe has been through a pulling-over operation and through the operation of side lasting. In accordance with common practice, an insole H3 is first placed on the bottom of a last 12 and secured there by means of tacks l4. An upper l5 is then slipped over the last, centered thereon and held in position by a single tack l5 driven through the heel seam joint. Following these operations the upper stock is tensioned over the last in the pullingover operation involving the use of a pullingover machine. During this process the machine drives a group of tacks 18 through the upper stock and insole margin and into the bottom of the last to hold the upper in position preparatory to the lasting operations which follow.

In the lasting operations the upper stock is finally conformed to the last and the margin thereof is secured to the insole. This is usually, although not always, carried out in three separate operations: toe lasting, side lasting and heel seat lasting. Side lasting is usually carried out from approximately the heel breast line to or beyond the ball line of the shoe. In Fig. 1 the shoe has been side lasted with a staple side lasting machine operating to drive staples 20 through the upper stock and the base of the insole rib 22, clinching them over on the inner side of the rib. The order in which the lasting operations are carried out varies with manufacturers, some preferring to carry out the toe lasting operation before side lasting. It is common for the heel seat lasting operation to be the last of the three.

In toe lasting the upper stock at the toe end of the shoe, comprising outer leather 24, doubler 26, box toe stiffener 28 and lining 3D, is wiped smoothly over the toe end of the last and inwardly over the feather or margin of the insole against the insole rib 22 in which position it is secured to the insole. In accordance with the illustrated practice of the invention, this is accomplished by placing the toe end of the shoe in a bed lasting type machine modified in the manner to be described, at which time, while the shoe is in the machine after the upper stock has been wiped upwardly of the last and is uniformly conformed thereto, the tacks [8 may be removed, whereafter the inward wiping motion will be executed to bring the upper stock inwardly over the insole margin and against the insole rib 22 preparatory to securing it there. These preparatory steps will be carried out preferably in the usual manner and will leave the shoe in a. finally conformed condition in relation to the last, and while it is thus held by the lasting means the stiffener piece may be activated to give a permanent shape to the toe end of the shoe and the upper stock may be secured to the insole by activation of the lasting adhesive. The invention provides for carrying out both of these steps at the same time, by the application of a high-frequency field configured to pass through the bonding adhesive and uniformly through the thermoactive stiffener blank, and it is the combining of these steps in such a way as to avoid separate handlings of the shoe, in a manner which lends itself to a single machine operation, that lends efficiency to the method of the invention. Preferably the field will be applied while the shoe is under the influence of the lasting or wiping means in order that the parts may most conveniently be held in lasted relation during the application of the field and the setting up of the stiffener and of the adhesive.

In implementing the method a bed lastin machine of the type previously referred to, as shown in Fig. 5, has been modified to the extent of incorporating high-frequency energy supply means in operative relation to the lasting means of the machine. The lasting means and the electrode apparatus are shown in some detail in Fig. 2, in perspective, which also illustrates the selected manner of conducting high-frequency energy to the electrodes in such a way that a minimum loss of energy will occur through radiation and through pickup on the surrounding parts of the machine.

It has been preferred to adapt the machine to the purposes of the invention with the least amount of alteration. Consistent with this preference the usual wipers 32 have been employed, without modification, as an element of the electrode system, although it may in some instances be desirable to modify the shape or construction of these members somewhat to alter the configuration of the field, or otherwise, to alter their electrical properties. Modification is not necessary basically, however, and by retaining the original shape of the wipers their desirable mechanical and functional properties are desirably preserved. In the views of Figs. 2, 3 and 4 the wipers 32, serving as one electrode in the system, are positioned to hold the upper stock in lasted relation to the insole and last and are thus in readiness for the application of a high-frequency field to the work parts.

The usual toe rest of the bed lasting machine, in the figures, has been replaced by a toe rest 34 which incorporates a second electrode 36 of the system. This electrode is preferably embedded in the rest beneath its upper surface and hence out of direct contact with the top of the shoe upper in order to avoid leaving an impression in the leather which otherwise might occur because of the downward pressure against the toe rest exerted with the use of the wipers 32. The material of the body portion of the toe rest may comprise any low-loss dielectric substance such as polystyrene or low-loss rubber, although the latter is preferred because of the yielding properties it d has which will'provide' a more" or less uniform cradling effect in supporting the shoe. Depending upon the amount of yield of the rubber, the electrode member 36 will preferably be set back a predetermined distance from the upper surface of the rest 34 which distance will usually be less than a quarter of an inch.

The details of construction of the toe rest incorporating electrode 36 will be most apparent from Fig. 2. Here the toe rest 34 has been dovetailed into a base member 38 carried on the upper end of an adjustable standard at conventional with the bed lasting type machine. The electrode member 36, comprising a central conductor extending lengthwise of the pad and lengthwise of the shoe will be approximately centrally located with respect thereto, and a pair of electrode crosspieces will be connected to the lengthwise conductor, substantially as shown. This electrode, thus embedded in the toe rest member 34, has an electrical extension 42 extending free of the member 34 for connection to the highfrequency energy source. In accordance with the illustrated construction of this electrode member 36 the longitudinal conductor terminates at a point near the tip line of a shoe at which point one cross member is located, and at a point roughly half-way between there and the end of the longitudinal conductive member the second cross member is located. The length of the cross members may be in the order of one inch, for example, a dimension which has been found desirable with this form of electrode, suiting the electrode particularly to mens shoes within a range of standard sizes. While this particular electrode shape has been found suitable for the purpose, in so far as it provides, in cooperation with the other electrodes, a uniform heating effect in the box toe stiffener material by setting up a rather evenly distributed field throughout such material, there are other arrangements which will be equally suitable. Any electrode which produces a relatively uniform field in this manner through the stiffener material and through the adhesive may readily be adapted for the purpose of the invention.

Cooperating with the wipers and the toe pad electrode members, which are preferably connected to ground for R. F. voltages, will be a third or intervening electrode member 44 disposed to lie adjacent to areas of the shoe upper between the overlasted margin and the shoe top and to extend around the forepart of the shoe approximately from points on either side lying between the ball line and the tip line thereof, the latter position being shown in Fig. 3. For convenience in construction and mounting, this member 44 may be formed of a single wire-like conductor forming a loop spaced from the shoe and the ends of which are brought together and clamped to the inner end of the toe rest member 34 by means of a clamping plate 46 and screws 48. In a practical application, as indicated in Figs. 2 and 4, the plane of the forward, horizontally disposed portion of the loop, which is U-shaped, will lie between the general planes of electrodes 32 and 36, preferably somewhat nearer to the latter to the end of producing the desired uniformity of field in the stiffener material. The inner, heightwise portion of the loop will be formed by the two inwardly and downwardly extending branches of the conductor which are curved to conform substantially to the cross sectional shape of the shoe in a transverse plane. It will be apparent that the exact configuration 8'. and proportions of the loop conductor used in serving as the intervening electrode will depend in large measure upon the chosen shape of the electrode member 36 and upon the style of shoe, 1. e., whether a pointed or square toe shoe, but the particular combination selected for illustration herein has been found to be eflicacious. Electrically,the electrode member 44 will be connected to the high-voltage side of the source of high-frequency energy and for this reason it may be preferable to provide a suitable low-loss insulating sheath or cover about the conductor to minimize the danger of burning the shoe through arcing. The insulated electrode member 44 is shown in cross section in Fig. 4 which is a cross sectional view through the shoe and electrode members taken on the line IV-IV of Fig. 3

looking forwardly of the shoe, although shown to a larger scale.

In connection with electrically energizing the electrode system, it has already been stated that the outside (toe pad and wiper) electrodes are preferably placed at ground potential and the intervening electrode member connected to a high voltage point. Conveniently, and in the preferred manner the energy will be supplied from a suitable oscillator source over a coaxial transmission line terminating at a point close to the electrodes, making possible the use of very short, flexible conductors to complete the connections. These are shown in some detail in Fig. 2, wherein a coaxial transmission line having an outer tu bular grounded conductor 50 and an inner coaxial high voltage conductor 52 is brought up to the vicinity of the electrodes from a high-frequency oscillator contained within a cabinet 54. Between the ends of the coaxial transmission line and electrodes are provided flexible braided conductors 56, 58 and 69, the first two of which are connected to the grounded conductor of the transmission line and the latter to the highvoltage inner conductor thereof, running respectively to electrodes 32, 36 and 44. These flexible conductors have been provided with suitable terminal lugs connected by screws to the parts of the machine. Separate grounding conductors 56 and 58 have been found desirable for the elec-' trode members 32 and 36 in minimizing the radiation and pickup resulting from currents flowing on the exposed conductors and electrodes.

Referring momentarily to Fig. 5, the coaxial transmission line has been provided with a pair of tuning stubs 62 and 6 3 spaced apart, in one practical case, approximately one-fifth wave length along the line, for the purpose of matching the electrical impedance of the load comprising the shoe placed in the electrodes to the im-- pedance of the line which in turn is matched to the oscillator, for the optimum condition of power transfer. The use of tuning stubs for matching purposes is well known and need not be described, an impedance match being thus obtained by an appropriate positioning of slidable tuning plungers 66 and 68 frictionally retained within the stubs. These plungers act as shortcircuiting connections between the inner and outer coaxial conductors of the stubs and in effect serve to set up counter reflections in the line which combine with the reflections from the load to efiect cancellation of the latter in accordance with the understood effect of matching impedances by means of transmission lines or Wave guides.

With the electrodes supplied with high-frequency energy from the oscillator, a field will-be set up in the stiffener material, including areas thereof between the lasting margin and the shoe top, and in the cement layers applied to the upper stock in the lasting margin. The field will extend between electrode member 44 and electrode members 32 and 36 respectively for activating stiffener areas between the overlasted margin of the upper and the shoe top. While the member 44 will usually be spaced a certain distance from the surface of the shoe, depending upon the size of the latter in a given application, there will be a large component of field which will traverse this distance, passing into the work and from there to another of the electrodes. This type of field has been referred to as a stray field and the use thereof makes possible the positioning of all the electrodes externally of the shoe and last, a desirable feature of the electrode system of the invention. In effect, the electrode arrangement is believed to be self-shielding, in so far as concerns radiation and pickup from the system, which are substantially avoided. This may be explainable on the basis of the balanced construction, i. e., the tendency of the two components of field extending between the intervening electrode, upwardly to the upper and downwardly to the lower electrodes, acting in opposition to each other effectively to prevent a net field of radiation.

In using the machine of Fig. in the practice of the invention, a last carrying a shoe in process of manufacture will be placed on a last pin HI (Fig. 2) adapted to engage a spindle hole in the heel portion of the last. The last pin will be mounted on the upper end of a jack F2 in the usual manner. With the position of the jack and of the toe pad standard 40 appropriately determined, the shoe will then be positioned symmetrically with respect to the electrodes and in operative position. Thus, the operator, by means of a treadle l4 and a hand lever 16 provided with the machine, may operate the wipers 32 to perform the lasting operation to the point of bringing the upper stock into lasted position (Fig. 4) bearing against the insole and insole rib of the shoe. Operating the treadle 14 produces an upward wiping stroke which acts to work the leather and underlying layers of the material uniformly over the toe end of the last and into conformation therewith, which is carried out while pressure is applied to the hand lever it to hold the wipers into close engagement with the shoe material. A further movement of the treadle M will bring the bottom of the wipers up over the plane of the insole bottom in order that a further movement of the hand lever 155 will cause the wipers to contract further and advance to wipe the marginal portion of the upper stock inwardly of the last and the insole margin and against the insole rib. Releasing the treadle and causing it to move in a clockwise direction will depress the wipers bringing them to press against the upper stock for holding it in lasted position. At this time, the operator, either by means of an automatic switching device operated from the treadle and, for example, controlled as in United states Letters Patent No. 2,379,059, granted June 26, 1945, upon the application of Ashley and Ryan, or by means of any suitable hand switch (not shown), will turn on the high-frequency oscillator to produce a field in activating the adhesive and stiffener materials. In order to remove the human e1ement manner of determining the appropriate amount of heat in the work, a suitable timer may be provided in the oscillator control circuits which 10 will be initiated with the turning on of high-froquency power and will automatically switch off the power at the end of a predetermined heating interval.

Among the advantages of the invention, as aforesaid, is that of its being adapted for application to existing machines with a Very minimum amount of alteration. In the case of the apparatus of Fig. 5, as herein described, the principal alterations or additions comprise those associated with incorporating the electrodes in the manner described, the provision of a bracket member 18 for supporting the coaxial transmission line and, if desired, a bracket member for supporting the high-frequency oscillator cabinet 54.

It will be appreciated that the invention, its broad aspects, is not limited to toe lasting but may also be applied to heel seat lasting or to side lasting if it be desired to do so. Likewise the particular instrumentalities by means of which the shoe may be worked over a last and/or the heat produced or a field set up in the stiffener and in the adhesive may vary. These and other aspects of the invention will be appreciated from a consideration of the foregoing disclosure and will be pointed out with particularity in the following claims.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent of the United States is:

1. That improvement in methods of making shoes, which comprises working different layers of shoe upper materials including a layer of thermoactive stiifener material in an initially limp condition into lasted relation to a last and an insole on the last with a thermoactive adhesive between the marginal portions of the upper materials and the insole, and while initially holding the upper materials in that relation. to the last and insole establishing a high-frequency electric field simultaneously in areas of said stiifener material lying between the said marginal portions and the shoe top and in said adhesive to effect stiffening of the former and to bond together the shoe parts in lasted relation by means of the adhesive.

2. That improvement in methods of making shoes comprising the steps of working the shoe upper materials into lasted relation with the last and insole on the last, the shoe upper materials including a limp, thermoactive stiffener material and a marginal layer of thermoactive adhesive between the upper and insole, and while initially holding the upper materials in said relation, applying a high-frequency field to the shoe parts simultaneously for activating the adhesive and areas of the stiffener material lying between the overlasted margin of the upper and the shoe top, to preserve the lasted relationship of the parts by means of the resulting bond and to impart permanent stiffness and form to the shoe upper.

3. That improvement in methods of making shoes, which comprises the steps, in connection with a lasting operation, of positioning the shoe for lasting, working a portion of the shoe upper stock into lasted relation to the last and insole on the last, and simultaneously activating a limp thermoactive stiffener layer previously incorporated into the shoe upper in areas lying between the overlasted margin and the shoe top and a layer of thermoactive adhesive between the margins of the upper and insole before the shoe is removed from said lasting position. I

, 4. The method of making a shoe on a last which comprises working difierent layer of shoe upper materials including a layer of thermoactive stiffener material in an initially limp condition into lasted relation to the last with a layer of thermoactive adhesive between the marginal portions of the upper materials and a sole on the last, and while holding the upper materials in that relation to the last subjecting all portions of the shoe upper materials under treatment including said adhesive and including areas of stiffener material lying between the overlasted margin of the upper and the shoe top to the action of a high-frequency field substantially concomitantly to activate the layer of stiffener material and the thermoactive adhesive to form a lasting bond securing the shoe upper and sole in their lasted relation and to impart permanent stiffness and form to the upper.

5. The method of making shoes comprising the steps of incorporating a layer of limp, thermoactive stiffener material into the upper of a shoe in a region thereof to be stiffened, applying the upper to a last with an insole placed on the last bottom, working the upper into conformation with the last and pressing the marginal upper stock contiguous to said region against the bottom of the insole marginally with a coating of pre-applied thermoactive adhesive between said insole and upper stock, and while the upper stock is thus pressed against the margin of the insole, setting up a high-frequency electric field in said cement and in the thermoactive stiffener material lying between the overlasted margin of the upper and the .shoe top to activate said adhesive for bonding together the upper stock and insole in lasted relation and to produce stiffening of said thermoactive stiffener material.

6. The method of making shoes which comprises utilizing wipers in working different layers of shoe upper materials including a layer of thermoactive stiffener material in an initially limp condition into lasted relation to a last and toan insole on the last with a thermoactive adhesive between the marginal portions of the upper materials and the insole, and while initially holding the upper materials in that relation to the last and insole by means of pressure applied to the wipers, setting up a high-frequency field between an electrode embodied in the wipers and a cooperative electrode disposed to lie adjacent to areas of the upper between its overlasted margin and the shoe top to activate said adhesive in forming a bond between upper materials and the insole and to activate said thermoactive stiffener material to produce stiffening thereof.

'7. That improvement in methods of making shoes with stiffened upper portions which comprises the step, after the assembling of a shoe with an upper held initially in lasted relation to an insole on a last, with a layer of thermoactive adhesive between upper and insole and with a readily conformable layer of thermoactive stiffener material incorporated into the upper in a selected area, of subjecting the shoe parts, including areas of stifien'er material lying between the overlasted margin of the upper and the shoe top, to the heating efiect of a high-frequency field in activating said adhesive and stiffener material with the same application of field.

. 8. Apparatus for the manufacture of shoes having stiffened upper portions, comprising wiper means, means for supporting a shoe on a last and for positioning the same operatively with respect to said wiper means, the upper of the shoe incorporating limp thermoactive stiffener material, an electrode embodied in said wiper means, cooperative electrode means disposed to lie adjacent to areas of the upper between its overlasted margin and the shoe top, and a means for connecting'said electrodes to a source of high-frequency energy for the -activation of said material with the shoe upperheld in lasted relation to the insole by means of said wipers.

9. Apparatus for the manufacture of shoes having stilfened upper portions, comprising lasting means for working a shoe upper into lasted relation to a last and insole on the last with a marginal layer of adhesive between the insole and upper, the shoe upper incorporating a layer of initially limp thermoactive stiffening material, an electrode embodied in said lasting means, a cooperative electrode disposed to lie adjacent to areas of the upper between its overlasted margin and the shoe top, and means for supplying high-frequency energy to said electrodes to activate said adhesive and stiffener material while the shoe parts are held in lasted relation under the pressure of said lasting means to effect a bond between the insole and upper and to stiffen said upper in lasting said shoe.

10. In a machine for performing a lasting operation on shoes in process of manufacture, the combination comprising wiper means, means for receiving a shoe on a last and for positioning the shoe operatively with respect to said wiper means, the shoe upper incorporating limp, thermoactive stiffening material, support means associated with said receiving and positioning means for supporting the shoe against the pressure of said wiper means, electrodes embodied in said wiper means and said support means, cooperative electrode means positioned adjacent to the outside of the shoe at a location between the first-named electrodes, means for connecting a grounded terminal of a source of highfrequency electric energy to said first-named electrodes and to the machine as a whole, and means for connecting a high-voltage terminal of said source to said cooperative electrode means, whereby said thermoactive material may be activated for stiffening purposes during the time the shoe is in the machine and under the influence of the wipers.

11. In a machine adapted for cement lasting a shoe which has been provided with an adhesive between the insole of the shoe and the overlasted margin of the upper thereof and which incorporates a layer of initially limp thermoactive stiffening material in the upper thereof, lasting means for engaging under pressure in one position of operation the overlasted margin of the upper, an electrode embodied in said lasting means, cooperative electrodes, both said portion to be stiffened and said adhesive lying the field region of said electrodes, and means for connecting a source of high-frequency electric energy to said electrodes.

12. In a machine for cement lasting and for permanently stiffening a portion of the upper of a shoe incorporating a layer of initially limp thermoactive stiffener material, the shoe being provided with an adhesive between the insole margin and the overlasted margin of the upper thereof, a lasting device for engaging under pressure in one position of operation the overlasted margin of the upper, an electrode embodied in said lasting device, a shoe rest for supporting the shoe against pressure from said lasting means, an electrode embodied in said shoe rest, a third electrode positioned between said shoe-rest electrode and said lasting-means electrode, means for connecting a grounded output terminal of a source of high-frequency energy to the frame of the machine and to the two outer electrodes, and means for connecting a high-voltage output terminal of the source to said third electrode.

13. In apparatus for the activation of a thermoactive stiffener material incorporated in a portion of the upper of a shoe on a last, an apparatus frame, means for positioning the shoe thereon, electrode means arranged to set up a field in said portion of a shoe so positioned, said electrode means comprising a first electrode positioned adjacent to said shoe near one extreme of said portion which is to be stiffened, a second electrode positioned adjacent to said shoe near an opposite extreme of said portion, and a third electrode positioned adjacent to said shoe intermediate to said first and second electrodes, means for connecting a grounded output terminal of a source of high-frequency electric energy to said frame and to said first and second electrodes, and means for connecting a high-voltage output terminal of said source to said third electrode, whereby said stiffener material may be activated by the field so produced.

14. In apparatus for the activation of a thermoactive stiffener material incorporated in the end portion of a partially lasted shoe, an apparatus frame, a shoe jack mounted on said frame and adapted for engaging a shoe last to position the shoe operatively in said apparatus, wiper means for bringing the shoe upper into lasted position, a shoe rest, electrode means to set up a field in the end portion under treatment of said shoe when in lasted position, said electrode means comprising a first electrode embodied in said wiper means and extending at least partly around the bottom of the end portion of the shoe, a second electrode embodied in said shoe rest, and a third electrode extending around said end portion of the shoe at a location intermediate to said first and second electrodes, and means for connecting a grounded output terminal of a source of high-frequency electric energy to said frame and to said first and second electrodes and a high-voltage output terminal thereof to said third electrode.

15. Apparatus as in claim 14 in which the shoe rest electrode comprises a longitudinally extending conductive member and a pair of spaced conductive cross members connected thereto.

16. Apparatus adapted for the activation of thermoactive stiffener material incorporated in the toe end of a shoe upper, comprising Wipers embodying a first grounded electrode, a toe rest embodying a second grounded electrode lying opposite the upper area of the tip of the shoe, and a U-shaped high-voltage electrode for positioning at an intermediate level around the outside of said toe end.

17. In apparatus adapted for a purpose described, the combination comprising a pair of curved plates for engaging an overlasted shoe upper at an end of the shoe, a first electrode embodied in said plates, and a second electrode comprising a looped member extending around the outside of the shoe end, cooperating with said first electrode.

18. In apparatus adapted for a purpose described, the combination comprising a toe rest embodying an electrode, said electrode comprising a conductive member disposed lengthwise of a shoe positioned against the toe rest, and additionally comprising sidewise conductive extensions of said member, and a cooperative electrode comprising a looped member extending around the outside of the toe end of said shoe, one side of the loop being curved in substantial conformity with the transverse curvature of the shoe near the tip line thereof.

19. In apparatus adapted for a purpose described, a toe rest of dielectric material, a grounded electrode embedded in said toe rest near the shoe-engaging surface thereof, and a second electrode surrounding said embedded electrode.

20. Apparatus as in claim 19 in which the toe rest electrode comprises a longitudinally extending conductive member having transverse extensions connected thereto.

ROBERT M. OSBORN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,145,979 Eldridge July 13, 1915 2,255,000 Haber et al Sept. 2, 1941 2,379,059 Ashley et al. June 26, 1945 2,406,738 Brophy Sept. 3, 1946 

